Alternating current vertical welder



Dec. 13, 1949 E. A. HOBART ETAL 2,490,371

ALTERNATING CURRENT VERTICAL WELDER Original Filed Feb. 11, 1947 2 sheds-sheet 1 INVENTORS .EDWARD A. HOBART 8 RUSSELL T. .FLORA ATTORNEYS 1949 E. A. HOBART ETAL 2,490,871

ALTERNATING CURRENT VERTICAL WELDER Original Filed Feb. 11, 1947 2 Sheets-Sheet 2 2s v as 38 INVENTORS EDWARD A. HOBART 8 RUSSELL T. FLORA BY UM Hula-am 3 Town:

this invention is best shown.

Patented Dec. 13, 1949 ALTERNATING comm VERTICAL wemsa Edward A. Hobart and Russell '1'. Flora, Troy,

Ohi

o, assignors to The Hobart Brothers Company, Troy, Ohio, a corporation of Ohio Original application Feb 727,830, now Patent August 31, 1948, Serial ruary 11, 1947, Serial No.

No. 2,457,372, dated December 28, 1948. Divld ed and this application No. 46,938

4 Claims. (Cl. 171-119) This invention pertains to improvements in controls for welding transformers. This application is a division of my application #727,830, filed February 11, 1947, which on December 28, 1948, issued as Patent #2,457,372.

More particularly, this invention pertains to a method of adapting a uniformly scaled dial, for indicating the number of amperes being produced in a welding apparatus, to a welding transformer in which the rate that the amperes are given 011 is not uniform but one that varies according to the position of the transformer coils.

In welding transformers, the amperage varies according to the proximity of the primary and secondary coils. When these coils are intheir closest relationship, the output of amperes is highest. As the primary coil is moved away from the secondary coil, the quantity of amperes produced decreases at a rapid rate at first, but at a slower rate as the coils are moved farther apart. This change in rate of amperes produced would ordinarily require that the dial used in connection with the welding transformer to indicate the amperes being produced at any given time would necessarily have to be one incorporating a graduated scale in order to compensate for this changing rate. I

Accordingly, an object of this invention is to incorporate, in connection with a welding transformer, a dial capable of using a standard, uniformly graduated scale to indicate the number of amperes being produced in the welding apparatus.

Another object of this invention is to decrease the possibility of mistakes occurring in welding operations caused by incorrect dial readings, by making possible the use of an easily read, uniformly scaled dial instead of the more dimcultly read, variably scaled dial.

Further features and advantages of this invention will appear from a detailed description of the drawings in which:

Figure 1 is a side view of a welding transformer incorporating the features of this invention.

Figure 2 is a front view of the upper portion of the welding transformer shown by the line 2-2 of Figure 1.

Figure 3 is a sectional and descriptive view shown by the line 3-3 of Figures 1 and 4.

Figure 4 is a top ,view of the welding transformer shown by the line 4-4 of Figure 3.

Referring particularly to Figure 3, the welding transformer incorporating the features of The apparatus comprises a base ill to which are attached frame supports II. From each frame support H, extending upwards in a slanting direction, is a pair of angle irons or frame members l2 and II. The base of the front angle iron of the pair of angle irons I2 is connected by a cross member l4 to the base of the front angle iron of the pair l3. The bases of the rear angle iron of each pair of angle irons i2 and iii are similarly connected. The cross members M are securely bolted at it. The tops of the pairs of frame members i2 and 83 are similarly connected by cross members l4, Figure 4. The cross members it are held together by the bolts IT.

A core i8, referring again to Figure 3, is positioned between the pair of angle irons l2, the cross members I! (note Figure 4), a strip I9, and the cross members H. A core 20 is similarly positioned between the pair of angle irons l3, the cross members i8 (note Figure 4), a strip Na, and the cross members l4. The secondary coil 2| is suitably fixed on the cross members i 4 by the clamping bolts 22. Theprimary coil 23 is guided for vertical movement on the strips l 9 and lie of the core members I! and 20. This movement is effected by a screw 24 and nut 25 fixed to the coil 23. The cores I8 and 20 both pass through the transformer coils 2| and 23. The primary coil 23 may be moved up or down on the screw 24 by movement of the knob 26 fixed to the cap 21, which cap is suitably fastened by a nut 24a to the screw 24.

An angle iron functioning as an arm 28 is fixed to the primary coil 23 by the bolt and nut arrangement 29. An arm 3i fixed to an eccentrically shaped pulley 43 is placed on the cross members it, Figure 4, so that the screw 24 passes through the center of the eccentrically shaped pulley 42 in such a manner that the movements of the screw 24 and of the eccentrlcally shaped pulley 48 are independent of each other. To the end of the arm 3! is attached a semi-circular metal band 33. To this band 33 is secured a card 34 on which is printed a uniformly graduated scale. Also fixed to the cross members I! are eyelets 38 by which the whole welding apparatus may be lifted.

A cover 42, Figure 2, is placed around the apparatus. In the cover 42 is a window 43 having a fixed indicator line 44 through its center.

Through the window 43 may be seen the card 34 on which the uniform scale is printed.

In operation, referring again to Figure 3, rotating the cap 21 by the knob 26 turns the screw 24 so that the primary coil 23 is either raised or lowered as desired.

around a cam or eccentrically-shaped pulley 48 secured to the arm 3|.

. placed around the screw 24 and resting on the cross members It has its ends secured to the rod A torsion coil spring 31 38, fixed to the cross members l8, and the rod 43, attached to the cam or eccentrically-shaped pulley 48. The pulls exerted on the cam 48 and:

arm 31 by the spring. and cable 38 are in oppo sition toone another.

The necessary variations in the distance that the card 34 must move in order to indicate the amperes being produced by the welding apparatus are caused by this cam arrangement. As the I primary coil 23 is moved away from the secondary coil 2 I, the cam or eccentrically-shaped pulley moves at first through great distances and then, as the coils become farther apart, through shorter distances. Thus, this arrangement provides a method for using a uniformly scaled card to indicate the amperes produced in a welding apparatus in which the rate of amperes given off is not uniform but one which varies, depending on the distance relationship of the transformer coils. Again this changing rate is'compensated for by the mechanism, in this case the cam arrangement, rather than by varying the graduations of the scale *used on the dial card.

While the apparatus herein disclosed and de-.

scribed constitutes a preferred form of the invention, it is to be understood that the apparatus is capable-of mechanical alteration without departing from the spirit of the invention and that such mechanical arrangements and commercial adaptations as-fall within the scope of the appendant claims are intended to be included herein.

What is claimed is: 1 v

1. In a welding transformer, a pair of relativelymovable'coils, nut and screw means operable to eflect said relative movement, a manually rotatable cap fixed to saidscrew, and a knob for rotating said cap, an indicating dial having a series of uniformly spaced indices, a fixed indicator line positioned relative to the indices on said dial, an eccentrically shaped pulley fixed to rotate with said dial, a cable attached to and operating over the eccentrical portion of said pulley and having its other end connected to one of said coils, ,and resilient means for normally rotating said dial and eccentrically shaped pulley to maintain said cable under tension so thatrelative movement of said coils upon rotation of said screw effects a non-uniform relative rotation of said dial and cap.

2. In a welding transformer having a frame, a coil fixed on said frame, a second coil movable on said frame relative to said first coil, a nut fixed to said second coil, a screw operating in said nut rotatably journaled against axial movement of said frame, a manually rotatable cap fixed to said screw for rotating said screw to cause relative movement of said coils, an indicating dial journaled for rotation about the axis of said screw, a series of uniformly spaced indices on said dial, a

reference line fixed on said frame in indicative relationship to said gradu'ations and means for rotating said dial upon actuation of said screw including a pulley fixed on said dial, an eccentrically shaped periphery on said pulley, a cable fixed to said pulley and operating over said eccentrically shaped periphery of said pulley, means for connecting the other end of said pulley to said second coil, and resilient means for normally I rotating said dial and eccentrically shaped pulley in a direction to maintain tension in said cable.

3. In a welding transformer, a fixed coil and a movable coil, nut and screw means connecting said coils operable to effect movement of said movable coil, manual means for rotating said screw for moving said movable coil into its several operative positions,'an indicating dial having a series of uniformly spaced indices thereon, afixed indicator line positioned relative to the indices on said dial, an eccentrically shaped pulley fixed to rotate with said dial, and flexible inextensible means having one end connected to said pulley and its other end connected with said movable coil and passing around the eccentric part of said pulley whereby uniform movement of said movable coil brought about by uniform rotation of said screw will be accompanied by a nonuniform movement of said dial.

4. In combination in a welding transformer having a fixed coil and a movable coil and manually operable means for moving the movable coil into its several operable positions; a housing enclosing said transformer having a window therein and a fixed indicator line extendingacross is established from said movable coil to said dial.

EDWARD A. HOBART. RUSSELL 'r. FLORA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 516,847 Thomson Mar. 20, 1894 597,180 Gates Jan. 11, 1898 2,438,202 Burns Mar. 23, 1948 2,457,372

Hobart Dec. 28, 1948 

